Device for dressing grinding wheels



March 26, 1935.- H. HALLAM 1,995,304

DEVICE FOR DRESSING GRINDING WHEELS Original Filed April 21, 1932 IPatented Mar. 26, 1935 DEVICEFOR' DRESSING GRINDING WHEELS Harry Hallam,Leicester, England, assignor to 7 United Shoe Machinery Corporation,Paterson, V N. .11, a corporation of New Jersey I OriginalapplicationApril 21, 1932, Serial No. I

606,69l.- Divided and this application May 29, 1934, SerialNo. 728,146.In Great Britain lvIa-y. 20, 1931 -5 Claims; (Cl. 125-11) Thisinvent onrelates to devices for dressing ahrading wheels and is hereinillustrated as embodied in an abrading machine of the characterdisclosed in my copending applicationfor Let ters Patent of the Uni-tedStates. Serial No. 606,691, filed April-21, 1932,- of which this appli:cation is a division. I 3 7 It is an obj ect' of the invention toprovide an improved device for dressing. grinding wheels, which devicemaybe conveniently operated and is so arranged as to render both itselfand the abrading tool readily accessible. In accordance with a featureof the invention, there is provided in combination with an abradingwheel a dressing tool I mounted for movement toward and from the wheel,means for pressing the dressing tool with predetermined force againstthe abrading wheel, means for normally holding the dressing wheel awayfrom the abrading wheel. and operatorcontrolled means for releasing thedressing tool from the holding means to render operatively the pressingmeans. In the illustrated machine, a relatively weak spring is providedfor urging the dressing tool toward the abrading wheel and a relativelystrong spring is provided for normally holding the dressing tool awayfrom the abrading wheel. The device is illustrated as mounted upon thehinged door of a dust hood associated with the abrading wheel, so thatwhen the door is open both the dressing device and the abrading wheelwill be readily accessible.

These and other features of the invention will be described as embodiedin an illustrative machine and pointed out in the appended claims.

Referring now to the accompanying drawing,

Fig. 1 is a view in front elevation showing the head of the machine; and

Fig. 2 is a view in side elevation of the seen in Fig. 1 looking fromthe left.

The frame of the illustrated machine comprises a vertical column 1having a head casting 3 at its upper end in which is supported ahorizontal shaft 5 extending from left to right of the operator as hestands in front of the machine. The

parts horizontal shaftis provided with fixed and idler pulleys 2 and 4,respectively, and a belt 6 driven from any suitable source of power maybe shifted from the idler pulley 4 to the fixed pulley 2 to start themachine. A grinding wheel 7 is secured to the left hand end of the shaftto be rotated thereby. A bracket 9 is secured to the machine head andextends close to the grinding wheel '7 and has bolted to it a circulardust collecting hood l1 enclosing the wheel 7. The hood 11 has an outletopening inits rear portion, from which outlet opening a suction conduit87 extendsdowm. wardly. The suction conduit 8'7 is connected to theusualexhaust blower (not shown) for disposing of dust which arises from theoperation of the wheel 7. upon the work. 7

In order. to prevent thesurface of the grinding wheel from becomingglazedby its grinding ac tion on insoles a dressing which can be.lowered into wheel 55 is provided contact with'the pe riphery of thewheel andserves by pressing on the ,latter to keepits surface'rough.This dressing wheel'g55 comprises anumber of corrugated steel discsmountedv side by side on a pin 5'7 which .is

secured in the rear end of "a rocker arm 59 which is housed inside thedust hood 11 and is secured at its forward end to a,freely rotatableshaft or pivot 61 whichextends throughthe left hand side of the dusthood surrounding the wheel. v A spring 63 is secured at one end to thearm 59 which carries the dressing'wheel to a hook on the dust hooddressing wheel down on to and at the other end and: tends to pull thethe periphery of the pin 67 secured to the hand lever 65.

A spring 73, which is stronger than the spring 63 which is connected tothe arm 59 carrying the dressing wheel, is secured to the hand lever 65and tends to pull the latter rearwardly so that the pin 67 secured tothe hand lever presses against the rearward end of the slot 71 formed inthe cap member 69 and thus lifts the arm 59 carrying the dressing wheelaway from the grinding wheel. By pulling the hand lever 65 forwardlyagainst the action of the spring 73 the pin 67 can be retracted from therearward end of the 510 the spring 73 to press the t 71; therebyenabling dressing tool against the grinding wheel. It will be noted thatthe pressure of the dressing toolagainst the grinding wheel is notderived from the lever 65 but from the spring 63, and is accordinglypredetermined. If, however, agreater pressure is desired, the operatorcan pull the lever 65 forwardly far enough to cause the pin '71 to bearagainst the forward end of the slot 71, thus transmitting additionalpressure to the dressing tool.

hand lever 65 is released Immediately the the dressing wheel is raisedowing to the rearward movement of the hand lever under the action isconnected to it.

of the spring 73 which In order to allow a free access to the grindingwheel the left hand side of the dust hood which carries the pivot 61 forthe link 59 is formed as a door '77 which is secured to the dust hood ona vertical pivot pin 79 near to its rear side. A thumb screw 81 normallyholds the door 77 clamped in closed position but by release of the thumbscrew the door can be swung open and the grinding Wheel can be easilyseen and reached.

Furthermore, when the door is open the dressing tool and its associatedmechanism are also accessible. Having described the invention, what isclaimed as new and desired to be secured by Letters Pat ent of theUnited States is:

1. In combination with an abrading wheel, a dressing tool mounted formovement toward and from the abrading wheel, means for pressing saiddressing tool with predetermined force against the abrading wheel, meansfor normally holding- -said dressing tool away from the abrading wheel,

dressing tool mounted for movement toward and from the abrading wheel, arelatively weak spring for urging said dressing tool toward the abradingwheel, an operating lever, a lost-motion con-' nection between saidoperating handle and said dressing tool, and a relatively strong springacting upon said operating lever in a direction to maintain saiddressing tool out of engagement with the abrading wheel, whereby, whensaid operating lever is manually moved in opposition to said relativelystrong spring said relatively weak spring will be free, by reason ofsaid lost-motion connection, to press said dressing tool withpredetermined for'ce against the abrading wheel.

4. An abrading machine comprising an abrading wheel, a dust hoodassociated with said abrad- 'ing wheel, a shaft journaled in andextending through a wall of said dust hood, an arm secured to said shaftwithin said dust hood, a dressing tool carried by said arm and movableinto engagement with said abrading tool upon swinging movement of saidarm, a relatively weak spring constructed and arranged to urge saiddressing tool toward said abrading wheel, an operating handle freelypivoted upon said shaft outside of said dust hood, a lost-motionconnection between said operating handle and said shaft, and arelatively strong spring acting upon said operating handle to cause theoperating handle, through said lost motionconnection, normally to holdsaid shaft in a position to maintain said dressing tool out ofengagement with said abrading wheelagainst the opposition of saidrelatively weak spring, said relatively weak spring serving, when theoperating handle is moved in opposition to said relatively strongspring, to press said dressing tool against said abrading wheel. 7

5; An abrading machine comprising an abrading wheel," a dust hoodpartially surrounding said wheel, said hood having a hinged dooradjacent to a side face of said wheel, a tool carried by said door fordressing the operating surface of said abrading wheel, andoperator-controlled means for causing said dressing tool to engage theoperating surface of said abrading wheel whensaid door is closed.

HARRY HALLAM.

